Re: Add Grub2 menu item without booting into GNU/Linux

[Robert]

Joshua Fox יהושע פוקס wrote:
> Greetings,
>
> I am trying to set up my Grub2 with Ubuntu 11.10.
>
> Grub2 was working, until I removed old kernels with Grub Conf.
> Though I took care not to remove the latest kernel, I find they
> are all missing.


your (sdb1)/boot/grub/grub.cfg  yet doesn't have a Linux boot 
entry on it. Just 2 memtest and XP Home. You erased too much.

> So, everything is OK-- but until I  add Ubuntu back into the Grub2
> boot menu, I cannot boot into it. (Some other entries, including
> memcheck and Windows, remain on the menu.)
>
> I tried Boot Repair, with no improvement: Here are the details on
> my machines boot configuration http://paste.debian.net/141706
>
> I also tried reconfiguring Grub2 after booting in LiveCD, to no avail.

How exactly?

In your live Environment you can simply mount your partitition 
with /boot on, and edit the /boot/grub/grub.cfg  - if you know 
what to add.

A) Yet, with your live CD you should be also able to boot your 
existing system (with live kernel). e.g. I know from Debian Live:
Press Tab on an apropriate Live boot menu entry, then you see a 
boot line, then replace all the options on the boot line with just 
e.g. root=/dev/sdb1 like:
"/live/vmlinuz <dont exactly remember> /live/initrd.img 
root=/dev/sdb1"

B) Also with the install CD you should have a resuce option to 
start a "shell in the target environment" or so.

C) Or in Live shell:

mount /dev/sdb1 /mnt
mount -o bind /dev /mnt/dev
mount -o bind /sys /mnt/sys
mount -o bind /proc /mnt/proc
chroot /mnt

=> then you are almost in your system "AS IF" you had booted into 
- at for this shell instance, in order to run update-grub or 
liloconfig.


As soon as you are into your Linux system/shell by A B or C, 
backup your grub.cfg, and re-run "update-grub". this auto-creates 
a rather complete grub.cfg, you can (reboot and) then again try to 
strip down the grub.cfg.


Or switch to LILO on that chance: "liloconfig".
LILO unlikely creates any such trouble (in the future). 
/etc/lilo.conf can be edited decently and all is rather clear and 
simple. And important: anytime you run lilo to really make your 
edits active (They are not before), LILO checks things actively or 
gives you errors or warnings BEFORE reboot. It doesn't install 
upon errors. And 99.9% doesn't install a unwanted/non-functional 
bootloader configuration, as you get feedback on the "lilo" run.


> What do I have to do?
>
> Regards,
>
> Joshua